code: def test_gradcheck(self, device, dtype):
      patches = torch.rand(2, 6, 64, 64, device=device, dtype=dtype)
      patches = utils.tensor_to_gradcheck_var(patches)  # to var
      defmo = DeFMO().to(patches.device, patches.dtype)
      assert gradcheck(
          defmo,
          (patches,),
          eps=1e-4,
          atol=1e-4,
          nondet_tol=1e-8,
          raise_exception=True,
          fast_mode=True,
      )
  
file_path: kornia/test/feature/test_defmo.py
imports: import pytest
  import torch
  from torch.autograd import gradcheck
  import kornia.testing
  from kornia.feature import DeFMO
  from kornia.testing import assert_close
label_desc: Use image node_id 3 for calling the TestDeFMO obj's underlying member method code with example usage: obj.test_gradcheck(device, dtype) without return types